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The Accidental Duplicator

Mission brief

Challenge Briefing

Medium

Self-Joins
Duplicate Logic

A bug caused duplicate transactions. Find all pairs of transactions (id1, id2) that have the same user_id, amount, and timestamp but different ids. Make sure id1 < id2.

The Accidental Duplicator

Find all pairs of duplicate transactions.

The Narrative

A bug caused duplicate transactions. Find all pairs of transactions (id1, id2) that have the same user_id, amount, and timestamp but different ids. Make sure id1 < id2.

Schema Diagram

transactions

idINT

user_idINT

amountDECIMAL

timestampDATETIME

Challenge a Friend

One SQL table. One SQL condition.
Still tricky for most developers.

SQL Editor

Terminal Output

Initializing Database Engine v1.8.0...

Write a SQL query, then click Run Query

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